Liquid cooled compliant heat sink and related method

Abstract

A heat sink and method for using the same for use in cooling an integrated circuit (IC) chip is provided herein. The heat sink includes a manifold block, a liquid-filled cooling system, and a compliant foil affixed to the manifold block and backed by a liquid in the closed loop cooling system. The pressure provided by the liquid behind the foil causes the foil to bow, and to conform to non-planarities in the surface of the IC chip, thus reducing air gaps and increasing thermal coupling between the IC chip and the heat sink.

What is claimed is: 
     
       1. A heat sink system for cooling an integrated circuit (IC) chip, the heat sink system comprising:
 a manifold block; 
 a liquid-filled cooling system including:
 a variable volume liquid-filled chamber positioned partially within and extending below the manifold block; and 
 a microjet device defining a portion of the variable volume liquid-filled chamber and introducing fluid into the variable volume liquid-filled chamber, the microjet device positioned within the manifold block; and 
 
 a compliant foil affixed to and positioned below the manifold block, the compliant foil thermally conductive and backed by a liquid in the variable volume liquid-filled chamber, wherein a pressure of the liquid on the compliant foil provides a uniform pressure by the compliant foil against the IC chip and causes the compliant foil to conform to a surface of the IC chip, 
 wherein the variable volume liquid-filled chamber is positioned between the compliant foil and the microjet device. 
 
     
     
       2. The heat sink system of  claim 1 , wherein the liquid-filled cooling system comprises a closed loop, the closed loop including:
 a refrigerated recirculator for chilling the liquid prior to circulating the liquid through the variable volume liquid-filled chamber; 
 an input port for liquid to enter the variable volume liquid-filled chamber through the manifold block and the microjet device; and 
 a return port for liquid to exit the variable volume liquid-filled chamber through the microjet device and the manifold block. 
 
     
     
       3. The heat sink system of  claim 1 , wherein the microjet device includes a plurality of supply jets for introducing the liquid behind the compliant foil at a pressure and a plurality of drains for removing the liquid from the variable volume liquid filled chamber. 
     
     
       4. The heat sink system of  claim 2 , wherein the microjet device includes a plurality of supply jets for introducing the liquid behind the compliant foil at a pressure, and a plurality of drains for returning the liquid through the return port to the refrigerated recirculator. 
     
     
       5. The heat sink system of  claim 1 , wherein the compliant foil comprises BeCu. 
     
     
       6. The heat sink system of  claim 1 , further including a liquid thermal interface (LTI) located between the compliant foil and the IC chip.